Note

A value .PBSmod$.options$.optionsChanged is set to TRUE when an option is changed,
so that the user doesn't always have to be prompted to save the options file.
By default, .PBSmod$.options$.optionsChanged is not set or NULL.
Also, if an option is set to "" or NULL then it is removed. .initPBSoptions() is now called first (options starting with a dot "."
do not set .optionsChanged).